I developed a spreading, itching rash on my chest the morning after I was in my hot tub, which is regularly treated with prescribed chemicals for the filters and the water. The rash started on my chest and has spread to my back and now downward to a limited extent on my extremities. The bumps are not pustules, there is no sign of bacterial infection, and the itching responds a bit to antihistamines. It tends to worsen at night, and the bumps redden, of course, after scratching. Discharge is minimal, and the bumps are small. Thoughts? YYYY@YYYY